chanty (n.)

1856, also shanty, chantey "song with a boisterous chorus, sung by sailors while heaving or hoisting anything heavy;" probably an alteration of French chanter "to sing," from Latin cantare "to sing" (from PIE root *kan- "to sing"). Perhaps the immediate source is French chantez, imperative of chanter. The purpose was to enable them to pull or heave together in time with the song.